For the female traveler, Bali is a safe island to discover on your own or in a group. On the whole, Balinese men are fairly benign to the appearance of Western women however we are seeing an increase in visitors from neighboring countries who have come to work on the building sites and in the fields that think nothing of wolf whistling, cat-calling, and making lewd propositions. Most of them are harmless but you should be vigilant when walking around at night in areas where these men hang out. The only people to be wary of are the Kuta cowboys, men who prey on woman looking to establish a relationship. For them, this is an opportunity to obtain some well-needed funds and have some fun at someone else's expense.
While traveling around the island, dress appropriately so as not to offend. While tight shorts and bare shoulders are acceptable on the beaches, they are frowned upon in the more rural areas.
For those traveling to Lombok, as long as you are respectful of their Muslim culture and dress appropriately you should not be bothered.
Bali and Lombok are generally safe and single travelers face no real threat or dangers. That said, don't throw common sense out of the window. Women on their own, in particular, should still be careful especially when out alone in the evening. Both men and women should beware of nightclubs where there have been a few cases of people having their drinks spiked. Never leave your drink unguarded or with a stranger.
Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.